eChapters

Southern Leaf Blight

Helminthosporium maydis (Syn: H. turcicum)

Economic Importance

• The first epidemics of the Southern corn leaf blight also known as Maydis leaf blight took place in the USA in 1970.
• A highly virulent strain called Race T appeared on maize hybrids with Texas male sterile cytoplasm.
• The disease development was related to the growing of maize with T-cytoplasm on large areas.
• Since 1990 the use of cultivars with T male sterile cytoplasm has been forbidden in selection.
• Presently, the cultivars with M and C types of sterility are used.

Common name, symptoms of damage and management of diseases of major spices and condiments

Okra/Ladies finger/Bhindi
1. Leaf blight/Spot
Pathogen
Cercospora abelmoschi Ell. & Ev.
Symptoms
The fungus grows as shooty to dark olivaceous, ectoparasite covering entire leaf lamina. Pathogen initiates as small isolated fungal growth on lower side of leaf but very soon it spreads on both sides. Pathogen reduces severely the photosynthesis area. Infected leaves fall down very quickly after dropping and rolling. It causes severe loss in seed production crop as well as in the late sown crops.

Introduction

The mango (Mangifera indica L.) is regarded as king of fruits. It is a key fruit crop in the subtropical regions of world including India. Prakash and Srivastava, 1987 reported that mango is attacked by more than 140 fungi (70 diseases), about 12 nematodes and a dozen of phanerogamic parasites and epiphytes. Among these diseases some major diseases of mango having economic important in India are briefly described in this chapter.

Anthracnose

Anthracnose is a severe disease of mango. High disease severity results to heavy loss including post-harvest losses during transit and marketing of produce. Mango anthracnose has been reported to spoil about 29 per cent of Alphanso fruits at Bangalore. Young plantations of Bombay green variety are completely wiped out in Tarai region of Uttar Pradesh as a result of severe wither tip Bose et al., 1973. At Lucknow, 24 per cent loss of fruits of Dashehari variety has been reported by Raoof and Prakash, 1984.

Mango (Mangifera indica) is a tropical fruit tree that is well-known and cherished for its delicious, sweet, and juicy fruit. It is one of the most widely grown and economically important fruit crops in the world, primarily cultivated in tropical and subtropical regions. Mangoes are not only enjoyed for their taste but also for their nutritional value, as they are rich in vitamins, minerals, and antioxidants.

However, like all agricultural crops, mangoes are susceptible to a range of diseases that can impact their growth, yield, and fruit quality. These diseases can be caused by various pathogens, including fungi, bacteria, viruses, and nematodes.

1. Powdery mildew (caused by Oidium mangiferae) is a fungal disease that affects mango trees, leading to significant losses in fruit production if left unmanaged.

Anthracnose

Colletotrichum gloeosporioides (Glomerella cingulata)

Diagnostic Symptoms

• Disease produces symptoms like leaf spot, blossom blight, withertip, twig blight and fruit rot

• Symptoms on leaves show as gray to brown spots with dark margins and a yellow halo. The spots later enlarge and coaleasce to form sizable necrotic areas.

Botrytis Gray Mould

Diagnostic Symptoms

• Appearance of a gray, fuzzy mold on flowers, leaves or stems of or plants. Also called, “gray mold”.

MINT (Mentha sp)
Fungal diseases
1. Stolon Rot
Symptoms: Yellowing of leaves is observed at early stage of infection. In later stage wilting of plants are noticed followed by drying of the entire plants.
Causal organism: Macrophomina phaseoli
Management
i) Stolons should be collected from healthy fields.
ii) Use of healthy and disease free stolons for planting.
ii) Treatment of stolons with Metalaxyl 8% + Mancozeb 64% WP (0.3%)
before planting.
2. Rust
Symptoms. In the spring or summer season the leaves and upper portion of stems are affected and become twisted. Yellow/ dusty orange pustules appear on the leaves and stems. In later part the pustules become black. Drying of leaves followed by defoliation occur.

FINGER MILLET (Eleusine coracana)
Fungal diseases
1) Blast
Symptoms: The above ground parts (leaf, leaf sheath, stems) of the plant exihibit the symptoms. The seedlings and adult plants are affected by the pathogen. Eye-shaped spots appear on leaf and leaf sheath having dark brown margin with ashy centre. These spots coalesce to form large patches and the leaves are blighted. Affected leaves wither prematurely and the seedlings may be killed. Lesions appear on the leaf blades, leaf sheaths and culms on adult plants and cause blightening.

Introduction

Mulberry (Morus spp.) is a most important crop which is used as food for silkworm (Bombyx mori L.) belonging to the genus Morus and family Moraceae. In tropical and temperate countries, mulberry is cultivated as shrubs and tree respectively. The total area under cultivation of mulberry in India is around 2,82,244 ha. The largest mulberry producing state is Karnataka (1,66,000 ha) followed by Andra Pradesh (38,084 ha). All over the world there are almost 68 species of Morus genus among 1000 varieties were commercially cultivated (Central silk board, Mysore). The nutritive values of mulberry leaves are affected by many diseases like leaf spot, powdery mildew, rust, root rot and bacterial blight which are causing severe yield loss up to 10-30%. In addition it also affects the growth, development of silkworm and cocoon yield due to feeding ofthose diseased leaves. (Sastry, 1984; Sundareswaran et al. 1998). Occurrence of these diseases based on some factors such as season, temperature, humidity and variety of mulberry (Sukumar, 1996). This chapter will be discussed about the disease causing organism, epidemiology and their management practices.

Cercospora leaf spot

Economic Importance

Cercospora leaf spot is an economically important disease causing abundant damage by reducing the leaf quality of mulberry (Siddaramaiah and Krishnaprasad, 1978). During July-December it causes yield loss of 10-15% and the disease present till January-February.

Introduction

Mulberry is a very hardy and fast growing perennial plant belonging to the genus Morus of the family Moraceae. The leaf of mulberry is used for feeding and rearing of the silkworm, for the production of silk yarn. It is estimated that mulberry silk worm (Bombyx mori) contributes around 90 % of the total global raw silk production and it is a very attractive economic activities mostly to the rural people. In addition to the utilization of mulberry leaves as silkworm feed, it is being used for many other purposes due to its high nutritive value and delicious taste is getting importance as valuable food stuff as well as environmental importance of mulberry taking into account several aspects of its role as animal feed, foodstuff, phyto medicine and remediation of polluted soils and atmosphere etc.

1 The clinical manifestations of disease of muscle, bones and joints are generally characterised by

a) Lameness b) Failure of support to stand

c) Incoordination of movement d) All of the above

The major functions of the musculoskeletal system to provide support to organs and help in physical activities including locomotion, prehension, and
mastication. The clinical manifestations of the diseases of muscles, bones and joints are much in common, and are generally characterized by lameness,
failure of support, in coordination of movement and deformity.

Diagnostic Symptoms

• Intially chlorotic (yellowed) lesions and sometimes galls appeared on the upper leaf surface.

• There are corresponding white blister-like dispersal pustules of sporangia on the underside of the leaf.

1 Delayed post natal diseases occurs within _______ days after birth

a) 10 days b) 2-7 days

c) 2 days d) 15-30 days

The diseases that occur during the first one month of life are termed as diseases of neonates. During this period, the animal requires special attention to reduce
mortality rate. The clinical examinations that are applied to adult animals are being used for the examination of newborns.

1 Inflammation of meninges and spinal cord along with brain is called

a) Encephalomyelitis b) Encephalitis

c) Meningitis d) Meningoencephalitis

The role of nervous system in animal is the maintance of bodies, speical relation with the immediate environment. Such functions are acomplished by several
sections of the nervous systsm. The sensory motor system is responsible for maintaing normal posture and gait.

Ozonium Wilt

Ozonium texanum var. parasiticum Thirum / Guizotia abyssinica

Economic Importance

• The disease was reported around Varanasi.
• Heavy losses are incurred as the diseased plants dry.

GROUNDNUT (Arachis hypogea)
Fungal diseases
1) Collar rot
Symptoms: The hypocotyls of germinating seeds are infected. The germinating seeds become covered with sooty black masses of spores. The infected tissues become dark brown and shredded. Necrosis and shredding of tissues may extend into branches.
The organism is both soil borne and seed borne.
Causal organism: Aspergillus niger
Management
i) Seed treatment with Carbendazim 50% WP @ 2-2. 5g/kg or Carboxin 37.5% WP +Thiram 37.5% WP @ 3gm/kg of seed.
ii) Growing of resistant varieties like Smruti

9.1. Groundnut

9.1.1. Early leaf spot: Cercospora arachidicola

1. Symptoms

Introduction

Okra (Abelmoschus esculentus L., Family: Malvaceae) also known as lady’s finger has been originated in Africa and introduced to India during early 20^th century. As an economical vegetable crop, it can be grown in tropical as well as sub-tropical parts of the world. During 2018-19, the total area under cultivation of okra was 511 thousand ha while the production stood at 6219 thousand MT in India (Horticulture Statistics Division, 2018). Okra can be grown on wide range of soils, but higher yield can be obtained in well-drained fertile soils with adequate organic matter. It is utilized for various purposes in terms of fresh leaves, buds, flowers, pods and stems providing a rich source of protein, carbohydrates, vitamins, calcium, potassium, enzymes, and total minerals in human diet. The mucilage has medicinal applications when used as a plasma replacement (Nilesh, et al., 2012), and the seeds contain 20 to 40% oil content (Sorapong, 2012).

Okra pods (per 100 g edible portion) are composed of water (88.6 g), energy (36 kcal), protein (2.10 g), carbohydrate (8.20 g), fat (0.20 g), fibre (1.70 g), Ca (84.00 mg), P (90.00 mg), Fe (1.20 mg), p-carotene (185.00 μg), riboflavin (0.08 mg), thiamine (0.04 mg), niacin (0.60 mg) and ascorbic acid (47.00 mg) ((Priya, et al., 2014).). Therefore, okra has been called as “a perfect villager’s vegetable” due to its robust nature, high dietary fibre as well as distinct seed protein with a balance of both lysine and tryptophan amino acids. Okra production is subjected to various diseases caused by fungi, virus and nematodes as a major biotic constraint. The mandates of integrated disease management of okra are to impart knowledge about symptoms, causal organism, disease cycle and epidemiology of major diseases. The present review will give a brief highlight about major diseases of okra viz. yellow vein mosaic, wilt, powdery mildew, cercospora leaf spot, damping off, collar rot and root knot nematode.

Introduction

Okra (Abelmoschus esculentus (L).is a cross pollinated vegetable crop. Okra originated near about Ethiopia& its cultivation became widespread in North Africa and the Middle East (Lamont, 1999; Tindal, 1983). Okra is grown commercially in many nations, such as Ethiopia, Cyprus, India, Bangladesh, Afghanistan, Pakistan, Turkey, Iran, Western Africa, Yugoslavia, Myanmar, Japan, Malaysia, Thailand, Brazil, Southern United States, and Ethiopia (Purseglove, 1987; benjawan et al. 2007; Qhureshi, 2007). It is a widely used, high-valued vegetable crop that is commercially grown for its tender pods during the spring, summer, and kharif seasons. Okra has high moisture content, making it a good source of vitamins, minerals, and mucilage. Okra is cultivated and consumed commercially throughout the year in many different places of India. 

Onion (Allium cepa) and garlic (Allium sativum) are monocots originating from Asia. These are collectively called as Alliums and formerly classified with the Liliaceae (lilies and relatives). But, now they have been classified in their own family the Alliaceae. The plants ofAlliaceae family are mostly used for seasoning and cooking. Some common crops in the family are bulb onion (Allium cepa), spring or salad onion (A. cepa), bunching onion (A. fistulosum), garlic (A. sativum), leek (A. porrum).

Onions and garlic are prone to several different diseases, especially in wet growing seasons. These often get started on their leaves, and if severe, can reduce bulb growth and yield. Another way onion diseases can cause damage is when they infect bulbs later in the season, which may lead to losses in storage. Some important diseases of onion and garlic are being discussed in this chapter:

Purple blotch

Alternaria porri

Diagnostic Symptoms

• Disease symptoms occurs on leaf and flower stalks.

Bulbous herb (Onion) that belongs to Alliaceae family and usually called as the “Queen of the Kitchen.” It is an important biennial vegetable crop grown in India with high export value. A crop that thrives in temperate climates where temperatures between 12.8 to 23°C are necessary for vegetative growth and 20 to 25? are required later for proper bulb development. Onion pungency is due to the presence of allyl-propyl-disulphide. The pigment quercetin and anthocyanin is responsible for yellow and red colour of onion. It has medical benefits like lowering disease risk of cardiovascular disease, diabetes and atherosclerosis. It possess antimicrobial, anti-inflammatory and antioxidant properties (Wilson and Demmig-Adams., 2007).The bulb is useful as diuretic and heart stimulant (Ahmad et al., 2016).

Plant diseases comprise a major factor in the culture of papaya. Adequate control measures are necessary to intensify the production of papaya. There are over 17 diseases caused by fungi, viruses, mycoplasma and nematodes, which affect papaya plant all over the world. Of these about 5-6 diseases like collar rot, damping off, anthracnose, mosaic and leaf curl are serious problems in many papaya growing areas of the world. They can reduce yield greatly and impair marketability of fruits. They must be checked and losses due to them must be minimized in order to increase the economics of papaya production.

Anthracnose

Economic Importance

Anthracnose is considered as one of the principle postharvest disease of papaya occurring worldwide and has been noted to cause huge losses in countries like Brazil, Hawaii (USA) and Mexico. It is one ofthe most ubiquitous and destructive disease of papaya, mainly during storage. The fungus infects various parts of the plant but mainly occurs in fruits, which later becomes unfit for commercialization. It is a major limitation to papaya production of about 90% along with the exportation of the fruit to bigger overseas market. The disease can have serious effect on refrigerated fruit for export. The use of inappropriate postharvest methods can result in production of up to 100% diseased fruits from some orchards.

Introduction

Carica papaya is a tree-like herb that grows 2 to 10 meters tall and is often unbranched, cylindrical & hollow stem Fruits are large, cylindrical, with fleshy orange pulp. Numerous, small, black, round seed with gelatinous aril. Papaya leaves have historically been used to treat thrombocytopenia brought on by a dengue infection. (Chinnappan et. al. 2016; Sharma et. al. 2019). Papaya fruits have healing capabilities against cancer, antimicrobial anti-malarial, anti-tumor, anti-inflammatory, antioxidant, immune-boosting, blood sugar-lowering, wound healing, gastro-protective, and capable of curing fever, asthma, jaundice, irregular menstruation, and beriberi. The pharmaceutical and wellness industries have seen a steady rise in demand for papaya as a result of researchers’ recent discovery of their therapeutic potential.

Pea (Pisum sativum L.) is considered as the important pulse and popular leguminous vegetable in India. Pea belongs to the genus Pisum, a member of family papilionaceae. Rhizobium bacterium found in root nodules that fixing atmospheric nitrogen and helps in soil fertility. Pea (Pisum sativum L.) originated in the near East and Mediterranean regions. Pea diseases are affect the crop both quantitatively as well as qualitatively. Pea crop diseases caused by the fungal (rust, powdery mildew, downy mildew, aschochyta blight, septoria blight, fusarium root rot, aphanomyces root rot, alternaria blight, wilt, anthracnose, cercospora leaf spot, damping off, seedling rot), bacterial (bacterial blight and brown spot), nematode (root-knot nematode, cyst nematode and lesion nematode) and viral diseases (pea enation mosaic, pea mosaic, pea seed borne mosaic, pea early browning virus, pea streak, pea stunt and cucumber mosaic virus). India is the largest producer, consumer and importer of pulses in the world.

Powdery Mildew

Erysiphe polygoni

Economic Importance

• Powdery mildew can be a serious disease of peas grown in India.
• It appears in epidemic form in the plains almost every year when the pods are formed in January-February.
• Since the disease occurs more frequently and covers a large host surface, it proves much more destructive than the downy mildew disease of the same crop.
• It is worst in dry weather as against the downy mildew, which flourishes in moist weather.
• Severe infections can reduce yield by 10–20%.
• Severe pod infection can lead to poor seed quality.

Powdery Mildew

Erysiphe polygoni

Diagnostic Symptoms

• At first symptom appears on leaves.

• White floury patches appear on both surface of leaves as well as tendrils, stem and pod.

Leaf Curl

Taphrina deformans

Disease Symptoms

• Initially yellowish to reddish areas appear on leaf blade of young leaves in the spring.

Introduction

Pear (Pyrus communis L.) is a temperate fruit that mainly grows in hilly areas at a elevation ranging from 1,500 to 2,500 metres. This temperate fruit is commonly eaten fresh or is canned. It is used to produce an alcoholic beverages and perry. The production of pear is 17 million tons per year in worldwide and the cultivation is expanding throughout the worldwide.

Pear cultivation is affected by many bacterial, fungal and viral diseases due to which it reduces the plant strength and decreases the quality of yield. Besides,pear can be also affected by many disorders and nematodes.

Bacterial Diseases

Fire blight

Fire blight disease is a serious concern to pear producers. It can destroy an entire orchard under optimal conditions in a single growing season.

Downy Mildew (Green Ear)

Sclerospora graminicola

Economic Importance

• Downy mildew is reported from temperate and tropical regions of the world.
• In India, the disease is a major stumbling block in the full exploitation of yield potential of hybrids.
• Several epidemics have been observed which resulted in substantial grain yield losses (upto 60 percent) in F₁ hybrids under South Indian conditions.
• Usually the losses in grain yield are directly proportional to disease incidence in the field.

Phosphorus is a critical mineral for animal health, playing a vital role in bone development, energy metabolism, cell signalling, and overall physiological functions. Disorders related to phosphorus imbalance, whether due to deficiency or excess, can lead to significant health issues in animals.
a) Pica
Pica is a condition characterized by the persistent ingestion of non-nutritive substances such as soil, rocks, plastic, cloth, or other inappropriate materials. While commonly observed in humans, pica is also prevalent in animals, including livestock, domestic pets, and wildlife. It is often a sign of underlying health, environmental, or nutritional issues. Understanding the causes, implications, and management of pica is crucial for animal welfare and productivity.
Causes of pica in animals
The aetiology of pica in animals is multifaceted and can be broadly categorized into nutritional, medical, behavioural, and environmental factors.

Introduction

Pineapple is one of the most important commercial fruit crop in India. It occupied an importance in the horticultural wealth and economy of the country. India ranked seventh among the pineapple producing country in the world during 2013-14 (GoI, 2014). It grows well in practically all type of soils with slightly acidic in nature, both in plain and hills. It is affected by several different pathogens wherever it grown and result in substantial crop losses. Some important diseases cause complete loss of the fruit marketableimportance. The major problems faced by pineapple growers in India are discussed below.

Pineapple (Ananas comosus) is an edible fruit bearing plant native to South America belonging to family Bromeliaceae. Pineapple is grown over an area of 1.06 million hectares with an annual production of 29.36 million metric tonnes (FAO, 2022). Pineapples are rich in vitamin C, minerals, fiber and low in calories. The enzyme bromelain present in pineapple is of considerable importance to the pharmaceutical and cosmetic industry (Varilla et al., 2021). The market for pineapples has been expanding significantly because of its appealing aroma compounds and nutritional benefits. The climate and distribution of rainfall in tropical and sub-tropical regions make these areas ideal for pineapple cultivation. Worldwide, Brazil is the leading producer of Pineapple followed by Philippines, Thailand, Costa Rica and India (FAO, 2022). In India the leading pineapple producing states are West Bengal, Northeastern region, Bihar, Kerala, Karnataka, Goa, and Maharashtra.This ‘Kew’ of Cayenne group and ‘Mauritius’ of the rough leaf Queen group are the two varieties dominating in India (Devi et al., 2013; Joy and Sindhu, 2012).

Botanically, Pineapple is a herbaceous perennial having short stem and tough waxy leaves. It produces a fleshy, edible, yellow fleshed which is a fusion of 100-200 berry like fruitlets. Most of the members of Bromeliaceae family are epiphytes i.e. grown on rocks and living trees though pineapples grow on the soil bearing sensitive adventitious root that cannot regenerate once damage and intolerant to poor soil aeration. The cultivated varieties of pineapple can be categorized into three groups namely, Cayenne, Queen, and Spanish. The Spanish and Cayenne groups can be cultivated for dual purposes viz. fresh fruit and canning. However, the Queen group are only cultivated for fresh fruit markets due to the presence of deep eyes making it unsuitable for canning (Devi et al., 2013).

12.1. Tea

12.1.1. Algal leaf spot: Cephaleuros virescens

Symptoms

• Leaves develop lesions that are roughly circular, raised and purple to reddish brown.

Management

• Removal of infected portions and spraying of Bordeaux mixture

• Improving soil nutrient status by application of nitrogen, phosphorus and potassium

12.1.2. Brown blight, grey blight: Colletotrichum sp., Pestalotiopsis sp.

Pomegranate (Punicagranatum L.) an extraordinary fruit crop that is cultivated worldwide with dominancy in Mediterranean countries like Morocco, Spain, Egypt, Iran, Afghanistan and Baluchistan since primordial times. Tropical and sub-tropical regions of the Indian sub-continent are the prominent areas under cultivation of this fruit crop. India plays a leading role in pomegranate production with contribution of nearly 50% of global production. The total area under pomegranate is 132 thousand hectare with annual production of 1357 thousand MT in 2014-2015.

Pomegranate (Punica granatum) a deciduous shrub in the family Lythraceae, subfamily Punicoideaeis one of the most adaptive sub-tropical fruit crop. It was introduced in the Indian subcontinent during 15^th century from the Mediterranean region of the globe. India holds the first rank as producer and exporter of pomegranate since last decade. Among the states, Maharashtra is the largest producer of Pomegranate (Punica granatum) in India. Pomegranate have an impressive nutrition profile it contains 7 grams fiber, 3 grams protein, 30% Vitamin C, 36% Vitamin K, 16% Folate and 12% Potassium. It also contains 24 grams of sugar and 144 calories. It contains two important compounds namely Punicalagins and Puninic acid. Along with the above nutritional advantages, it also has immense health benefits right from curing a fatal disease like cancer to remedying arthritis and joint pain. India stands first in the list of Pomegranate producer countries with respect to cultivation area. The states leading in pomegranate production in India are Maharashtra (70.2%), Karnataka (10%), Gujarat (7.4%), Andhra Pradesh (6.7%), Telangana (1.9%), Madhya Pradesh (1.9%), Tamil Nadu (1.0%) and Rajasthan (0.4%) (Source: Horticultural Statistics at Glance, 2015).

Introduction

Pomegranates are a tasty, juicy, sweet fruit that are rich in nutrients. Punica granatum is its scientific name, and Iran is where it was originally found. Because pomegranates may be cultivated effectively in regions of the nation with dry climates, they hold a distinctive place among the fruits that are grown there. Other names for pomegranates include Dadim in Sanskrit, Bedana in Bengali, Anar in Hindi, and Madulai in Tamil. The states of Maharashtra, Gujarat, Rajasthan, Karnataka, Andhra Pradesh, Tamil Nadu, and Uttar Pradesh are the primary locations for its cultivation. From the perspective of export, this fruit is also highly significant.

Pomegranate is referred to as a “Super Food” because of its many health and nutritional advantages. It is one of the greatest sources of antioxidants and has significant medicinal and nutritional value. Ripe fruit has a pleasant and nutritious juice. Juice from pomegranates in the summer, sherbet is incredibly refreshing. Pomegranates are regarded as a medication for long life and excellent health in the Ayurvedic medical system.

Introduction

Potato is mostly considered as a vegetable crop in India, whereas it is a staple food crop in Europe, Canada, Australia, U.S.A, South America, Russia, Asia and other countries. In India, it is cultivated extensively in the hilly tracts during December-March or March-June and in the plains during September-January, as it requires cool and moist climate condition. As per FAOSTAT (2015), the potato production in India during 2013 was 45.34 mt from 1.99 mha area with a productivity of 22.76 t/ha. There are several varieties of potato grown in India and many diseases, some of which cause considerable damage to the crop. Potato crop can be affected by diseases caused by fungi, bacteria, virus, viroids and others by non-parasitic.

Late Blight

Economic Importance: Late blight is one of the most devastating diseases of potato throughout the world. It is recorded in area with frequent cool and moist weather. The disease is believed to have been introduced into Europe from South and Central America and spread to other countries which include the East Coast of Canada, Western Europe, Central and Southern China, South Eastern Brazil and the tropical highland. It created history by causing a famine in Ireland known as Irish Famine during 1845-46 resulting in death of many people due to starvation, dysentery and typhus spread among the farmers and subsequent migration of people from Europe especially from Ireland. Late blight has the tremendous potential to cause upto 70% reduction in the yield in a susceptible cultivar. Region wise economic importance of late blight shows that the disease takes highest toll of potato in Sub-Saharan Africa (44% crop losses) followed by Latin America (36%), Caribbean (36%), South-East Asia (35%), South-West Asia (19%)

Late Blight

Phytophthora infestans

• Phytophthora in Greek means “plant destroyer”(phyto=plant, phthora= destroyer).

Introduction

Potato (Solanum tuberosum) is a widely cultivated and essential staple crop globally, known for its versatile culinary applications and nutritional value. With the exception of Kerala, potatoes are grown in practically every state in India under a variety of climatic circumstances. During the brief winter months, which span from October to March, 82% of potatoes are grown in plains. In West Bengal, potatoes are the most widely grown crop after grains (Chakraborty, 2012). Originating from the Andes region of South America, potatoes have become a crucial part of diets worldwide, providing carbohydrates, vitamins, and minerals. With a rich history dating back to ancient civilizations, including the Irish potato famine, this crop has played a significant role in shaping agricultural practices and food security.

8.1. Redgram

8.1.1. Wilt: Fusarium udum

1. Symptoms

GREEN GRAM (Vigna radiata) & BLACK GRAM (Vigna mungo)
Fungal diseases
1) Seed and seedling rot
Symptoms: The seeds rot before germination and after germination the seedlings also show rotting. The disease can be easily identified by poor germination and poor stand of the crop.
Causal organisms
i) Fusarium sp
ii) Pythium sp
iii) Rhizoctonia solani
iv) Macrophomina phaseoli
 

Health care and preventive hygiene in rabbits are very important for the productivity of the rabbits and economical viability of a farm.

It is always better to prevent the disease rather than to get an animal treated, which is usually quite expensive. As such it is desirable that the rabbits are checked daily. The health and ailment signs can be recognized from the following things:

Radish (Raphanus sativus) is a cool weather crop and its origin is in Mediterranean, rapid growing annual or biennial plant belongs to family Brassicaceae, grown for its edible taproot. Its edible roots are having different color from as white to red. Radish is generally grown as an annual plant, surviving only one growing season. It is crop of tropical and temperate region. It is growing as herb in West Bengal, Bihar, Uttar Pradesh, Karnataka, Punjab and Assam areas are major radish growing states. Radish is good source of vitamin B6, Calcium, copper, magnesium and riboflavin. Also it is rich in ascorbic acid, folic acid and potassium.

Alternaria Blight

Economic Importance

Alternaria leaf spot diseases occur in every part of the world, in both vegetable crops and seed crops and most important disease of Brassica species, often results in severe yield losses. It is considered as a number one disease of radish affecting both fresh vegetable and seed production. The disease is more severe when the plants are left for seed production in the field and causes significant reduction in seed yield. Alternaria black spot of radish; black pod blotch of radish. A. japonica is a seed-borne pathogen of plants in the Brassicaceae. A. japonica is known to affect most parts of infected plants depending upon growth stage. There are reports of it on the hypocotyls and cotyledons of seedlings and on the leaves, petioles, stem, inflorescence, fruits (siliquae) and seeds of adult plants. A. japonica occurs in all parts of radish (Raphanus sativus) seed. Its presence in the embryo can result in seed death, but in milder infections it will affect seedlings after germination, causing seedling blight both before and after emergence.

Anthracnose

Colletotrichum lindemuthianum (Sacc. & Magnus)

Glomerella lindemuthianum Shear

Economic Importance

• Anthracnose warrants a serious attention as it inflicts heavy economic losses to the crop, which may reach up to 100%, under conducive conditions.
• In India disease incidence has been reported to vary between 24.59 to 51.72 per cent.
• In Jammu region of Jammu and Kashmir state disease incidence of 63.46% was recorded.